Linked Questions

2 votes
1 answer
2k views

Finding power series solution for differential equation in Mathematica [duplicate]

I know this topic has been covered before, but I've tried all the solutions I can find from other users' questions and none of them have worked. I need to find a power series solution to the ...
user53707's user avatar
2 votes
2 answers
493 views

How to get the series coefficient of a function defined by a differential equation [duplicate]

I need a Taylor series approximation for $x(t)$, which is defined by the following differential equation. $\frac{dx}{dt}=-k_1 x+(1-x)k_2 e^{-k_3 t}$, $x(0)=0$ ...
Bravo's user avatar
  • 283
2 votes
1 answer
332 views

Solving for the coefficients of a series [duplicate]

Suppose I have a given series $A(z)=\Sigma a_nz^n$ I want to solve a differential equation for $B(z)$ in terms of coefficients of $a_n$ as a series. Possibly with ansatz $B(z)=\Sigma b_nz^n$ or other ...
Duke Smith's user avatar
1 vote
0 answers
625 views

Solving differential equations with sums (power series) [duplicate]

I have sets of 10 differential equations, but for this purpose I'll demonstrate what I need on one example that can be solved by hand. My equation is this: $$4GJ\Omega(\theta)\Omega'(\theta)\xi^\...
dingo_d's user avatar
  • 677
-1 votes
1 answer
384 views

How to find the power series solution of this ordinary differential equation using MMA [duplicate]

I already know that the solution of this differential equation $y''(x) - x*y(x) = 0$ can be expressed by the following power series: $$y(x)=c0(1+\frac{x^{3}}{2\times3}+\frac{x^{6}}{2\times3\times5\...
A little mouse on the pampas's user avatar
9 votes
3 answers
872 views

How do I find a series solution for $e^{-\frac{1}{2}f'(x)} \mathrm{cosh}( f(x) ) = ax + b$?

I am trying to approximate a function $f(x)$ satisfying a relation between $f(x)$ and its first derivative. How do I find a series solution for $$e^{-\frac{1}{2}f'(x)} \mathrm{cosh}( f(x) ) = ax + e^{-...
Quant's user avatar
  • 125
6 votes
3 answers
4k views

Solution of equation with power series (perturbation)

So I need to use Mathematica to find the solution of $y=x- \epsilon \sin(2y)$ as a power series in terms of $\epsilon$. I'd assume I'd need to create an equation $f=x-y- \epsilon \sin(2y)$, then ...
Lenny's user avatar
  • 61
10 votes
1 answer
982 views

Trouble with shooting method for a 4th-order differential equation

I'm trying to solve the following forth-order ODE with the shooting method: $$\frac{1}{5}(y-2xy^\prime)=\frac{1}{x}\left\{\frac{xy^\prime}{y}+xy^3 \left[\frac{(xy^\prime)^\prime}{x} \right]^\prime \...
W. Robin's user avatar
  • 491
0 votes
2 answers
5k views

How to solve the second order differential equation [duplicate]

I've been trying to do code this for a two or so hours, and I can't seem to do it. Please help.. I am trying to solve the following second-order differential equation: ...
John's user avatar
  • 3
2 votes
2 answers
695 views

DSolve not satisfying initial conditions

I am trying to solve the following nonlinear, non-homogeneous, first order ODE: $y'(t)=\sqrt{y(t)}-B$ $y(0)=B^2$ $B=const$ In code: ...
user64860's user avatar
  • 121
1 vote
2 answers
1k views

Solving recursion relation from power series

I am interested in solving differential equations in the form of power series. Let's say we have following equation: $$f^{\prime \prime} (\rho) + \left( \frac{2 e^{-k \rho}}{\rho} - \varepsilon \...
user16320's user avatar
  • 2,396
7 votes
1 answer
691 views

Trouble with shooting method for a 4th-order stiff ODE

The ODE I need to solve is $$\left(y^3y^{\prime\prime\prime}\right)^\prime+\frac{5}{8}xy^\prime-\frac{1}{2}y+\frac{c}{y}=0$$ where $\prime$ denotes differentiation, $c$ is a constant and $0<c\le1$....
W. Robin's user avatar
  • 491
0 votes
0 answers
906 views

Solving PDEs using Taylor series

I'm thinking of solving a Partial differential algebraic equation using multidimensional polynomial (i.e. Taylor series). Consider the PDAE: $$\mathbf F \left( \mathbf x, \mathbf y, \frac{\partial ...
Foad's user avatar
  • 615
0 votes
2 answers
407 views

Getting the coefficients of a series that solves a differential equations

I have an example from Stewart's Calculus where the equation $y'' + y = 0$ is solved using power series. The equation ...
BenNevis's user avatar
0 votes
1 answer
239 views

Differentiation of infinite series does not seem to be useful

Trying series solution of differential equations, the routine is to define a function as a series, and differentiate it. ...
梁國淦's user avatar
  • 392
1 vote
1 answer
130 views

Solving differential equation but keeping showing running

I am trying to solve this differential equation, see the command below. But the cell keeps showing that it is running without giving any answer for a very long time. Eventually I had to abort it. Does ...
Frank's user avatar
  • 11
0 votes
1 answer
97 views

Solving an NODE in series

How can I solve this NODE in series y''[x]^2 + (1/2)*y'[x] + (1/2) y[x] == p x + q. `p` and `q` are constant. But do not know how to actually solve it with ...
Bahram Agheli's user avatar
3 votes
0 answers
173 views

How to find a power series expansion of a function obeying a certain PDE?

Let us suppose that I have some differential operator $D_{x,y}$ acting on functions of two variables $(x,y)$. I want to solve one eigenvalue equation $$D_{x,y}f_{ij}(x,y)=\lambda_{i,j} f_{ij}(x,y).$$ ...
user1620696's user avatar
0 votes
1 answer
67 views

Successive solutions using previously found [closed]

is there a way to use previous calculated values of solve? solving equations based on asymptotic expansion $x^2+x-\varepsilon=0$ $x=x_0+\varepsilon x_1 + \varepsilon^2 x_2 + \varepsilon^3 x_3$ ...
2Napasa's user avatar
  • 103
0 votes
0 answers
107 views

How to make a code to find Taylor series symbolic solution to four coupled nonlinear differential equations?

I am trying to modify the existing code developed by Michael E2 in this question here. His solution was for one differential equation. I like his code because it has ability to solve nonlinear ...
Aschoolar's user avatar
  • 893
0 votes
0 answers
72 views

Recurrence relation of coeeficients of power series solution to DE

Say I have a DE $$ -\phi \left(\phi \left(\left(6975 \phi ^2-3704 \phi +160\right) \omega '(\phi )+\phi \left(\left(6975 \phi ^2-4688 \phi +266\right) \omega ''(\phi )+\phi \left(2 \left(...
Bernoulli's user avatar
  • 203